<template>
  <div>
    <h2>全选案例</h2>
    <label for="all">全选：</label>
    <input type="checkbox" id="all" v-model="xxx">
    <ul>
      <li v-for="item in arr" :key="item.name">
        <input type="checkbox" v-model="item.c" />
        <span>{{ item.name }}</span>
      </li>
    </ul>
    
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [
        { name: '猪八戒', c: false },
        { name: '孙悟空', c: false },
        { name: '唐僧', c: false },
        { name: '白龙马', c: false }
      ]
    }
  },
  computed: {
    xxx: {
      get () {
         return this.arr.every(item => item.c === true)
      },
      set (val) {
        this.arr.forEach(item => {
          item.c = val
        })
      }
    }
  }
}
</script>

<style>

</style>